Rubber Watch Straps
Rubber Watch Straps
Vulcanized rubber was a natural choice for watch manufacturers . It has excellent strength and resilience and easily returns to its original intended shape after bending. It resists wear and tear and oxidation. It repels fats, oils and other solvents, while also limiting water absorption. It has a wide temperature range making it flexible and reliable between −80 °C to +250 °C and won’t break down until it hits temperatures above 350 °C.
The watchmaking industry first began adding rubber bands to their timepieces in the 1950’s. Rolex, Tudor, and Blancpain were some of the early timepieces found with rubber bracelets. However, it wasn’t until the 1960’s that the use of rubber bands became mainstream, largely due to its usefulness on diver and sports watches. They also found their way onto other watches with the super-compressor cases patented by Ervin Piquerez SA (EPSA) in the 1950s. The original IWC Aquatimer (1967) also came with a Tropic strap to complement a stainless steel bracelet.
Rubber straps gained popularity in the 1970s and 1980s. Watches such as the Precimax Super-Dive and Aquastar Benthos 500 appeared on rubber – usually black rather than the bright blue, orange or yellow rubber watch strap so often seen today. In the 1980s, Italian manufacturer Bonetto Cinturini came onto the watchstrap scene. Just to confuse the issue, there are many different types of rubber!
Many of the early natural rubber straps didn’t perform well. The vulcanised nitrile rubber watch strap is still one of the most popular and widely used for high-performance applications. As with any rubber, its performance isn’t just determined by its type, be it Nitrile Butadiene Rubber (NBR), silicone rubber, polyurethene rubber or PVC rubber. Also important is the specific formulation.
This is a rubber-like material that seems to be less widely used for serious high-quality performance watch straps – with notable exceptions such as Sinn, who offer silicone rubber straps . While silicone can easily be shaped and coloured, it has a reputation for stickiness, a tendency to tear and propensity to attract dust and lint.
Shinier than polymers like PU rubber, this is a thermoplastic vinyl polymer that’s very durable, but lacks the characteristics for high-end applications that make NBR so appealing.
Polyurethene rubber (‘urethene’) is another polymer with elastic properties – an elastomer – comprising a chain of organic units linked by urethene (carbamate) links. They are very durable, highly functional, but sometimes reported to be less comfortable than natural rubber.
Over the years, other synthetic rubbers have been produced from petrochemical bases, including isoprene and neoprene. Both have a specialist following. In particular, isoprene straps enjoy a good reputation, but at a price that’s several times more than a top-quality vulcanised rubber watch strap.